Crystal structure of new synthetic Ca,Na,Li-carbonate-borate

In the process of studying the phase formation in the Li₂CO₃-CaO-B₂O₃-NaCl system, new Ca,Na, Li-carbonate-borate has been synthesized under hydrothermal conditions. The crystal structure of carbonate-borate with the crystallochemical formula Ca₄(Ca_0.7Na_0.3)₃(Na_0.7□ _0.3)Li₅[B ₁₂ ^t B ₁₀ ^Δ O₃₆(O,OH)₆](CO₃)(OH) · (OH,H₂O) was refined to R _hkl = 0.0716 by the least squares method in the isotropic approximation of atomic thermal vibrations without the preliminary knowledge of the chemical composition and the formula (sp. gr. R3, a _rh = 13.05(2) Å, α = 40.32(7)]°, V = 838(2) ų, a _h = 8.99(2), c _h = 35.91(2) Å, V = 2513(2) ų, Z = 3, d _calcd = 2.62 g/cm³, Syntex P $\bar 1$ diffractometer, 3459 reflections, 2θ-θ method, λMo). The structure has a new boron-oxygen radical [B ₁₂ ^t B ₁₀ ^Δ O₃₆(O,OH)₆] _∞∞ ^15? , a double layer of nine-membered [B ₆ ^t B ₃ ^Δ O₁₅(O,OH)₃]^7.5?-rings bound by BO₃-triangles, and twelve-membered [B ₆ ^t B ₆ ^Δ O_19.5(O,OH)₃]^7.5? rings. This allows one to relate this compound to megaborates with complex boron-oxygen radicals. The structure is built from two types of blocks consisting of Ca,Na,B-and Li,B-polyhedra alternating along the c-axis, which explains the perfect cleavage of the crystals along the (0001) plane.     

Reaction of 2,3-bis(diphenylphosphino)maleic acid-thioanhydride (bmata) with PhCCo3(CO)9. X-ray diffraction structure of {\text{Co}}_{\text{3}} ({\text{CO)}}_{\text{6}} [\mu _2 ,\eta ^2 ,\eta ^1 {\text{ - C(Ph)}}{\text{(O)](}}\mu _2 {\text{ - PPh}}_{\text{2}} )

The benzylidyne-capped cluster PhCCo₃(CO)₉ (1) reacts with the diphosphine ligand 2,3-bis(diphenylphosphino)maleic acid-thioanhydride (bmata) to afford ultimately the new cluster ${\text{Co}}_{\text{3}} ({\text{CO)}}_{\text{6}} [\mu _2 ,\eta ^2 ,\eta ^1 {\text{ - C(Ph)}}{\text{(O)](}}\mu _2 {\text{ - PPh}}_{\text{2}} )$ (3) in low yield under thermolysis conditions or by Me₃NO activation of PhCCo₃(CO)₉. The intermediate cluster compound PhCCo₃(CO)₇(bmata) (2) has been confirmed by IR spectroscopy and is shown to give ${\text{Co}}_{\text{3}} ({\text{CO)}}_{\text{6}} [\mu _2 ,\eta ^2 ,\eta ^1 {\text{ - C(Ph)}}{\text{(O)](}}\mu _2 {\text{ - PPh}}_{\text{2}} )$ upon heating. Cluster 3 has been isolated and characterized in solution by IR and ³¹P NMR spectroscopies, and the solid-state structure of 3 was established by X-ray diffraction analysis. ${\text{Co}}_{\text{3}} ({\text{CO)}}_{\text{6}} [\mu _2 ,\eta ^2 ,\eta ^1 {\text{ - C(Ph)}}{\text{(O)](}}\mu _2 {\text{ - PPh}}_{\text{2}} )$ crystallizes in the triclinic space group P ${\bar 1}$ , a = 11.6053(8) Å, b = 11.8438(8) Å, c = 15.099(1) Å, α = 105.169(5)^○, β = 90.530(5)^○, γ = 104.976(6)^○, V = 1928.5(2) ų, Z = 2, and d _calc = 1.578; R = 0.0442, R _w = 0.481 for 2591 observed reflections with I > 3σ (I). The cyclic voltammetric properties of 3 have been investigated and are contrasted with the related bma-derived cluster ${\text{Co}}_{\text{3}} ({\text{CO)}}_{\text{6}} [\mu _2 ,\eta ^2 ,\eta ^1 {\text{ - }}{\text{(O)OC(O)](}}\mu _2 {\text{ - PPh}}_{\text{2}} )$ .     

New phosphate Fe0.5Nb1.5(PO4)3 with an electrically neutral framework. Synthesis and crystal structure

A new iron-niobium phosphate, Fe_0.5Nb_1.5(PO₄)₃, has been prepared and studied by X-ray diffraction, electron microprobe analysis, IR spectroscopy, and neutron powder diffraction. On the basis of X-ray powder data, it was found that the synthesized phosphate crystallizes into the sp. gr. R $\bar 3$ c and corresponds to the structural type of sodium-zirconium phosphate NaZr₂(PO₄)₃. The structure was refined by the Rietveld method based on a powder neutron diffraction experiment. The obtained phosphate belongs to complex niobium orthophosphates and has a framework structure with a zero framework charge.     

New triclinic modification of lead iodate Pb(IO3)2: Synthesis and crystal structure

A new triclinic modification of lead iodate Pb(IO₃)₂ (space group $C\bar 1$ ) is obtained under hydrothermal conditions. The crystal structure is determined without preliminary knowledge of the chemical formula. [IO₃]^? groups, which are characteristic of pentavalent iodine, have a typical umbrella-like configuration. The new phase has a more complex structure than the known orthorhombic modification. The arrangement of heavy Pb and I atoms follows a’ = a/3 pseudoperiodicity. In the layers of two types that form sheets parallel to the ab plane, Pb and I atoms have different coordinations. A polytypic nature of the new modification is responsible for the one-dimensional disordering along the a axis as well as different variants of layer alternation. It is possible to obtain crystals of acentric and polar derivatives of the centrosymmetric phase that will be promising for application.     

Interaction of mercury(II) halides with tertiary phosphine betaines: synthesis and structural characterization of [HgX2{Ph3P(CH2)2CO2}] (X=Cl, I) and [HgCl(μ-Cl)-{Ph3P(CH2)3CO2}]2

Three new mercury(II) complexes containing tertiary phosphine betaine ligands Ph₃P⁺(CH₂)₂CO₂ ^? and Ph₃P⁺(CH₂)₃CO₂ ^? have been synthesized and fully characterized by single-crystal X-ray analysis: [HgCl₂{Ph₃(CH₂)₂CO₂}],1, space groupP2₁/n,a=9.819(2),b=14.966(4),c=14.973(5) Å, β=105.67(2)° andZ=4; [HgI₂{Ph₃(CH₂)₂CO₂}],2,P2₁/n,a=10.206(2),b=14.807(3),c=15.557(3) Å, β=107.11(2)° andZ=4; [HgCl(μ-Cl){Ph₃P(CH₂)₃CO₂}]₂,3, $P\bar 1$ ,a=10.813(2),b=11.975(3),c=11.180(2) Å, α=87.04(2), β=75.14(1), γ=81.95(1)° andZ=1. The isomorphous complexes1 and2 contain discrete mononuclear molecules in which the mercury(II) atom is unsymmetrically chelated by a Ph₃P⁺(CH₂)₂CO ₂ ^? ligand and coordinated by a pair of terminal halo ligands in a distorted tetrahedral environment, while3 consists of discrete centrosymmetric dinuclear molecules in which the betaine ligand Ph₂P⁺(CH₂)₃CO ₂ ^? acts in the chelate mode and the mercury(II) atoms are unsymmetrically bridged by a pair of chloro ligands.     

Crystal structure and IR spectroscopic study of (CN3H6)2[(UO2)2(C2O4)(CH3COO)4]

Compound (CN₃H₆)₂[(UO₂)₂(C₂O₄)(CH₃COO)₄] is synthesized and characterized by IR spectroscopy and single-crystal X-ray diffraction [a = 8.5264(2) Å, b = 13.8438(4) Å, c = 10.7284(2) Å, β = 103.543(1)°, space group P2₁/n, Z = 2, and R = 0.0258]. The main structural units of the crystals are binuclear [(UO₂)₂C₂O₄(CH₃COO)₄]^2? groups, which belong to the A ₂ K ⁰² B ₄ ⁰¹ crystal chemical group of uranyl complexes (A = UO ₂ ²⁺ , K ⁰² = C₂O ₄ ^2? , and B ⁰¹ = CH₃COO^?). The coordination polyhedron of the uranium atom is the UO₈ hexagonal bipyramid with the oxygen atoms of the uranyl ion at the axial positions. Uranium-containing groups and guanidinium cations are connected by electrostatic interactions and by the hydrogen bond system, which involves hydrogen atoms of guanidinium cations and oxygen atoms of oxalate and acetate anions. The results of the spectroscopic study of the compound agree with the X-ray diffraction data.     

Kinetics of hydrothermal crystallization of quartz in Na2CO3 solutions

The kinetics of crystallization of the {0001}c, {01 $\bar 1$ 1}r, and {10 $\bar 1$ 1}R faces of quartz in 0.5 M Na₂CO₃ (M is molarity) aqueous solutions has been studied in the temperature range 200–450°C. It is established that the dependence of the crystal growth rate on temperature in the logV-1/T, K coordinates is of a parabolic nature. It is most probable that the nonlinearity of this dependence is associated with a deficiency in the solution of silica monomers, taking part in the elementary event of quartz crystallization. The causes of a jumpwise decrease in the activation energy of the growth of the c, r, and R faces at t > 280–325°C are considered.     

Structure of {Pb[S2CN(C2H5)2]2(1,10-phenanthroline)}2

Lead (II) nitrate reacts with 1,10-phenanthroline and sodium diethyldithiocarbamate in water to produce yellow bisdiethyldithiocarbamata 1,10-phenanthroline lead(II). Crystals from water are triclinic, space group $P\bar 1$ (#2),a=10.53(2) Å,b=11.050(12)Å,c=24.74 (3) Å, α=94.71 (9)⁰, β=98.15(11)^o, γ=114.11(9)^o,V=2569(6) ų,Z=2. Each lead atom has approximate pentagonal pyramid coordination geometry through the nitrogens of a phenathroline and sulfurs of two dithiocarbamates. Additionally, complexes form loose dimers in which lead atoms are weakly coordinated to a sulfur in an adjacent complex. IR and proton nmr spectrum of the complex are consistent with the solid state structure.     

X-ray crystal and molecular structure of [3,6-bis(2-pyridyl)pyridazine-N 1,N2]bis(triphenylphosphine) copper(I) hexafluorophosphate

[3,6-bis(2-pyridyl)pyridazine-N ¹,N²]bis(triphenylphosphine) copper(I) hexafluorophosphate crystallizes in space group $P\bar 1$ with cell dimensionaa=14.050(2),b=11.941(2),c=15.200(2) Å, α=71.28(1), β=67.02(1), and γ=84.78(2)^o. In the title compound, the mononuclear cation consists of a tetrahedral copper(I) center involving two nitrogen donors of the 3,6-bis(2-pyridyl)pyridazine (dppn) and two P atoms of the triphenylphosphine molecules. In the dppn ligand the two non-coordinating N atoms (one from pyridine and one from pyridazine) are mutallytrans.     

Refined crystal structure of lovozerite Na2CaZr[Si6O12(OH,O)6] · H2O

The structure of Na,Ca,Zr-silicate lovozerite, Na₂CaZr[Si₆O₁₂(OH,O)₆] · H₂O, from the Khibiny alkaline massif (the Kola Peninsula) was refined by single-crystal X-ray diffraction analysis (Syntex $P\bar 1$ diffractometer, λMoK _α radiation, 2θ/θ scanning technique). The refinement (R _hkl = 0.077, 1531 independent reflections; anisotropic thermal parameters) confirmed the trigonal system proposed for the mineral earlier (sp. gr. R3; a = 10.18(1) Å, c = 13.13(2) Å, Z = 3) and revealed the presence of two additional positions (C and B) statistically occupied by Ca and Na atoms (and partly by Mn) and H₂O molecules, respectively.     

Phase transitions in Cs5(HSO4)2(H2PO4)3 crystal

The symmetry (sp. gr.I $\bar 4$ 3d) and lattice parameters have been determined for the first time for Cs₅(H₂SO₄)₂(H₂PO₄)₃ crystals in the temperature range from 172 to 390 K. The thermal and optical properties of crystals, as well as their conductivity, have been investigated at elevated temperatures. It is shown that a crystal heated to T = 365 K undergoes a phase transition with symmetry lowering to the tetragonal phase (with the parameters a = 4.965(1) Å and c = 5.016(1) Å), while at T ≈ 390 K a phase transition to the cubic phase is presumably observed. With a decrease in temperature, a phase transition without a change in symmetry occurs at T = 240 K.     

Crystal structure of [Rb0.24(H2O)0.76]VO(H2O)(PO4), a new monoclinic variety in the series of layered vanadyl phosphates

The crystal structure of a new monoclinic variety of hydrous rubidium vanadyl phosphate [Rb_0.24(H₂O)_0.76]VO(H₂O)(PO₄) doped with Al³⁺ ions is studied by X-ray (R = 0.054) diffraction: a = 6.2655(4) Å, b = 6.2712(3) Å, c = 6.8569(5) Å, β = 107.805(7)°, space group P2₁/m, Z = 2, and D _x = 2.792 g/cm³. The new phase obtained by the hydrothermal synthesis in the V₂O₅-Rb₂CO₃-AlPO₄-H₂O system has a layer-type structure in which Rb atoms and water molecules are located between layers of vertexsharing [VO₅(H₂O)] octahedra and [PO₄] tetrahedra. Rb intercalates based on VOPO₄ · 2H₂O are described by general formula [Rb _x (H₂O)_{1 ? x} ]V _1?x ^V V _x ^IV O(H₂O)(PO₄), where x ≤ 0.5, and the amount of reduced vanadium and interlayer water molecules is determined by the amount of introduced rubidium atoms.     

X-Ray diffraction and IR-spectroscopic studies of UO2(n-C3H7COO)2(H2O)2 and Mg(H2O)6[UO2(n-C3H7COO)3]2

Single crystals of UO₂(n-C₃H₇COO)₂(H₂O)₂ (I) and Mg(H₂O)₆[UO₂(n-C₃H₇COO)₃]₂ (II) are synthesized. Their IR-spectroscopic and X-ray diffraction studies are performed. Crystals I are monoclinic, a = 9.8124(7) Å, b = 19.2394(14) Å, c = 12.9251(11) Å, β = 122.423(1)°, space group P2₁/c, Z = 6, and R = 0.0268. Crystals II are cubic, a = 15.6935(6) Å, space group $Pa\bar 3$ , Z = 4, and R = 0.0173. The main structural units of I and II are [UO₂(C₃H₇COO)₂(H₂O)₂] molecules and [UO₂(C₃H₇COO)₃]^? anionic complexes, respectively, which belong to AB ₂ ⁰¹ M ₂ ¹ (I) and AB ₃ ⁰¹ (II) crystal chemical groups of uranyl complexes (A = UO ₂ ²⁺ , B ⁰¹ = C₃H₇COO^?, and M ¹ = H₂O). A crystal chemical analysis of UO₂ L ₂ · nH₂O compounds, where L is a carboxylate ion, is performed.     

Refined crystal structure of iron-rich triclinic astrophyllite

Crystal structure of Fe-rich triclinic astrophyllite K₂NaFe₇ [Ti₂Si₈O₂₆F](OH)₄ is refined (a Syntex P $\bar 1$ automatic diffractometer, 3809 reflections, 2θ/θ scan, R = 0.041): a = 5.365(2), b = 11.88(1), c = 21.03(2) Å, α = 84.87(6)°, β = 92.25(5)°, γ = 103.01(4)°, sp. gr. A $\bar 1$ , Z = 2, d _calcd = 3.29 g/cm³. The refined structure is identical to that reported earlier. The structure is built by three-layer TOT sheets in which an O layer of Fe-octahedra is sandwiched between the T layers consisting of Si-tetrahedra and Ti-octahedra. It is established that differently chosen unit cells of the mineral are interrelated.     

Synthesis and crystal structure of new phosphate NaFe 4 2+ Fe 3 3+ [PO4]6

New sodium iron orthophosphate NaFe ₄ ²⁺ Fe ₃ ³⁺ [PO₄]₆ was synthesized by the hydrothermal method. The crystal structure (sp. gr. $P\bar 1$ ) was established by the heavy-atom method, with the exact chemical formula of the compound being unknown; R _hkl = 0.0492, R _whkl = 0.0544, S = 0.52. The new compound is analogous to iron phosphate Fe ₃ ²⁺ Fe ₄ ³⁺ [PO₄]₆ studied earlier. However, these two compounds differ in the Fe²⁺ and Fe³⁺ contents, because Na⁺ ions in the new compound are located at the centers of symmetry not occupied earlier.     

Preparation and crystal structure of the new ionic bis-[hydrazido]-molybdenum complex [Mo(NNPh2)2(acac)(PPh3)2]+OTf−

The title compound [Mo(NNPh₂)₂ (acac)(PPH₃)₂]⁺OTf^?, Mr=1233.1, crystallizes in the triclinic space group $P\bar 1$ , witha=12.881 (4),b=13.795(3),c=17.160(5)Å, α=90.95(1), β=91.31(1), ψ=103.53(1)°, andZ=2. The structure was solved by Patterson methods, and refined with some difficulties due to extensive disorder in the counterion. The Mo ion is hexacoordinated in an octahedral environment, with two O and two N defining the basal plane, and two P atoms in the apical sites.     

Crystal structure of Zn4Na(OH)6SO4Cl·6H2O

The structure of Zn₄Na(OH)₆SO₄Cl·6H₂O, a secondary mineral from Hettstedt, Germany, was determined by single-crystal X-ray diffraction. The crystals are hexagonal,a=8.413(8),c=13.095(24) Å, space group $P\bar 3$ , Z=2. The structure was refined to R=0.0554 and R_w=0.0903 for 970 reflections with I≥3σ(I). The structure can be described as zinc hydroxide layers perpendicular toc, from which sulfates and chlorides extend. The layers are held together by a system of hydrogen bonds involving hexaaquo Na⁺ ions which occupy the interlayer space.     

Crystal structure of litvinskite: A new natural representative of the lovozerite group

A new representative of the lovozerite group—Na, Zr, Mn-silicate litvinskite (Na, H₂O, □) ₃(□, Na, Mn²⁺)Zr[Si₆O₁₂(OH)₃(OH, O)₃]—was discovered in ultraagpaitic pegmatites from the Lovozero massif. The crystal structure of the mineral was solved on an automated Syntex P $\bar 1$ diffractometer (MoK _α radiation, 1398 reflections, 2θ/θ scanning technique, anisotropic refinement to R _hkl = 0.065). The unit-cell parameters are a = 10.589(7) Å, b = 10.217(8) Å, c = 7.355(5) Å, β = 92.91(5)°, V = 794.6(9) ų, sp. gr. Cm, Z = 2, d _calcd = 2.63 g/cm³. The structure of the mineral consist of a three-dimensional framework of discrete six-membered rings of Si-tetrahedra linked to isolated Zr-octahedra. The framework cavities are occupied by Na cations. The litvinskite composition and the structure differ from all known natural and synthetic compounds of the lovozerite group, which supports the assumption about diversity of mineral types in this group.     

Hole defects in the crystal structure of synthetic lipscombite (Fe 4.7 3+ Fe 2.3 2+ )[PO4]4O2.7(OH)1.3 and genetic crystal chemistry of minerals of the lipscombite-barbosalite series

The crystal structure of a synthetic analog of the mineral lipscombite (Fe _2.3 ²⁺ Fe _4.7 ³⁺ )[PO₄]₄O_2.7(OH)_1.3 obtained under hydrothermal conditions in the LiF-Fe₂O₃-(NH₄)₂HPO₄-H₂O system is resolved (R = 0.040) by X-ray diffraction analysis (Bruker Smart diffractometer with a highly sensitive CCD detector, MoK _α radiation): a = 14.776(3) Å, b = 14.959(3) Å, c = 7.394(1) Å, β = 119.188(4)°, sp. gr. C2/c, Z = 4, ρ_exp = 3.8 g/cm³, ρ_calcd = 3.9 g/cm³. Fe²⁺ and Fe³⁺ cations are statistically distributed in each of four crystallographically independent positions, while occupying the corresponding octahedra with probabilities of 60, 90, 100, and 91%. The ratio Fe²⁺/Fe³⁺ in the composition of the crystals was established by Mössbauer spectroscopy. Lipscombite is interpreted as a mineral of variable composition described by the formula (Fe _x ²⁺ Fe _n?x ³⁺ )[PO₄]₄O_y(OH)_4?y . The field of stability is determined as a function of the iron content and the ratio Fe²⁺/Fe³⁺. It is shown that at n = 6 iron cations are ordered in octahedra and barbosalite structure is formed. An interpretation of genetically and structurally related members of the lipscombite family within a unified polysomatic series is proposed.     

Crystal structure of tisinalite Na2(Mn,Ca)1 − x (Ti,Zr,Nb,Fe3+)[Si6O8(O,OH)10]

Crystal structure of tisinalite from the Lovozero alkaline massif (the Kola Peninsula) was established by single-crystal X-ray diffraction analysis (SYNTEX $\bar P1$ diffractometer, λMoK_α radiation, 2θ/θ scanning mode). The structure solution (SHELX97 program package, R _hkl = 0.0565, 951 independent reflections, anisotropic refinement of thermal atomic displacements) confirmed that tisinalite belongs to the lovozerite structure type (sp. gr., $\bar P1$ , a = 10.036(5) Å, c = 12.876(9) Å, Z = 3). The difference between the structure of tisinalite and the structures of the minerals of the lovozerite group established earlier consists in the nature of the occupancy of both cation and anion positions.